There has been an increase in vibriosis in the U.S. since May 2013.

As of September 30, 104 cases of a specific strain in 13 states with 6 hospitalizations and no deaths were reported to CDC.

Vibrio bacteria live in saltwater. People can get vibriosis after eating raw or undercooked shellfish, particularly oysters. Several species of Vibrio, including Vibrio parahaemolyticus, can cause illness.

There has been an increase in infections caused by a specific strain of Vibrio parahaemolyticus.

These infections occurred among people who, in the week before they became ill, ate raw oysters or raw clams harvested along the Atlantic Coast.

Before 2012, Vibrio parahaemolyticus infections of this strain were rarely associated with shellfish from the Atlantic coast.

Symptoms typically consist of mild to moderate diarrhea, but can sometimes be severe, especially if the bacteria enter the bloodstream.